// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_ANDROID_BACKGROUND_SYNC_NETWORK_OBSERVER_ANDROID_H_
#define CONTENT_BROWSER_ANDROID_BACKGROUND_SYNC_NETWORK_OBSERVER_ANDROID_H_

#include "base/android/jni_android.h"
#include "base/android/scoped_java_ref.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "content/browser/background_sync/background_sync_network_observer.h"
#include "content/public/browser/browser_thread.h"

namespace content {

// BackgroundSyncNetworkObserverAndroid is a specialized
// BackgroundSyncNetworkObserver which is backed by a NetworkChangeNotifier
// that listens for network events even when the browser is paused, unlike the
// standard NetworkChangeNotifier. This ensures that sync events can be fired
// even when the browser is backgrounded, and other network observers are
// disabled.
class BackgroundSyncNetworkObserverAndroid
    : public BackgroundSyncNetworkObserver {
public:
    // Creates a BackgroundSyncNetworkObserver. |network_changed_callback| is
    // called via PostMessage when the network connection changes.
    BackgroundSyncNetworkObserverAndroid(
        const base::Closure& network_changed_callback);

    ~BackgroundSyncNetworkObserverAndroid() override;

    // This class lives on the UI thread and mediates all access to the Java
    // BackgroundSyncNetworkObserver, which it creates and owns. It is in turn
    // owned by the BackgroundSyncNetworkObserverAndroid.
    class Observer : public base::RefCountedThreadSafe<
                         BackgroundSyncNetworkObserverAndroid::Observer,
                         content::BrowserThread::DeleteOnUIThread> {
    public:
        static scoped_refptr<BackgroundSyncNetworkObserverAndroid::Observer> Create(
            base::Callback<void(net::NetworkChangeNotifier::ConnectionType)>
                callback);

        static bool RegisterNetworkObserver(JNIEnv* env);

        // Called from BackgroundSyncNetworkObserver.java over JNI whenever the
        // connection type changes. This updates the current connection type seen by
        // this class and calls the |network_changed_callback| provided to the
        // constructor, on the IO thread, with the new connection type.
        void NotifyConnectionTypeChanged(
            JNIEnv* env,
            const base::android::JavaParamRef<jobject>& jcaller,
            jint new_connection_type);

    private:
        friend struct BrowserThread::DeleteOnThread<BrowserThread::UI>;
        friend class base::DeleteHelper<
            BackgroundSyncNetworkObserverAndroid::Observer>;

        Observer(base::Callback<void(net::NetworkChangeNotifier::ConnectionType)>
                callback);
        void Init();
        ~Observer();

        // This callback is to be run on the IO thread whenever the connection type
        // changes.
        base::Callback<void(net::NetworkChangeNotifier::ConnectionType)> callback_;
        base::android::ScopedJavaGlobalRef<jobject> j_observer_;

        DISALLOW_COPY_AND_ASSIGN(Observer);
    };

private:
    // Accessed on UI Thread
    scoped_refptr<Observer> observer_;

    base::WeakPtrFactory<BackgroundSyncNetworkObserverAndroid> weak_ptr_factory_;
};

} // namespace content

#endif // CONTENT_BROWSER_ANDROID_BACKGROUND_SYNC_NETWORK_OBSERVER_ANDROID_H_
